Specifications

CHAPTER 2
Hardware Design
14 Hardware Overview
Figure 2-4 Detailed block diagram—7"
PCI muxed
address/
data bus
Macintosh
PCI bus
connector
[31:0]
Data
32
Address[31:0]
A[4:16]
Data
cache
Buffer
Connector
Game port
Connector
Video
buffer
168-pin DRAM
DIMM
PCI muxed
address/
data bus
Optional
audio cable
Ribbon cable
for video out
5x86-class
processor
PCI muxed address/data bus
Memory
data
Memory
address
Address
Memory data[63:0]
Tag
data
8
[31:0]
[31:0]
Memory
address (12)
XA[23:0]
XD[7:0]
Cache
tags
VGA
accelerator
(built-in
RAMDAC)
SIO ISA
bus
Video
DRAM
1 MB
Memory
controller &

PCI bridge
Sound Blaster
compatible
audio IC
(plus game timer)
8242
keyboard
control
Mustard ASIC
PCI bus bridge I/F
Address translation
Keyboard/mouse emulation
Serial ports A/B emulation
Parallel port emulation
PC legacy logic
Message mailbox
Reset block
Interrupt register and mask
9
18
26
1
10
19
Video
mux
External
loopback
Macintosh
video in
Macintosh/PC
video out
Audio Audio
Berlin adapter
video buffering
GIMO
connector